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The circumference of a circle calculator is an online tool that helps us calculate the circumference of a circle in multiple ways. The circumference of the circle can be calculated if the radius of the circle, or the diameter of the circle is known to us. The radius or diameter can also be calculated if the circumference of the circle is given to us. Before we get into these methods, let us familiarize ourselves with the calculator....Read MoreRead Less

**1.**

Enter the known input into one input field only and rest will be calculated.

If you enter the radius as input, then the diameter and circumference will be calculated.

If you enter diameter as input, then radius and circumference will be calculated.

If you enter circumference as input, then radius and diameter will be calculated.

**2.**

Select the appropriate unit for the input and output.

**3.**

You can also select the desired value of pi from the dropdown box: 3.14, \(\pi\) or \(\frac{22}{7}\).

**4.**

Now, click on “Solve” to obtain the result.

**5.**

You can check “Show steps” by clicking in the box to understand the stepwise method for obtaining the answer.

**6.**

You can click on the reset button to reset the input and output values. You can repeat the above steps for some other input values.

**7.**

Click on the “Example” button to play with different random input values.

**8.**

Click on the “Explore” button to visualize how a diameter is related to the circumference of a circle.

**9.**

When on the “Explore” page, click on the “Calculate” button if you want to go back to the calculator.

A circle is a two-dimensional round figure. All of the points on the circle’s boundary are equidistant from the circle’s center.

The circumference or perimeter of a circle is the measurement of the boundary of the circle.

Imagine the boundary of a circle were to be cut open and laid on a flat surface. Now, measure the boundary of the circle as if it were a string; the length thus measured would be the circumference of the circle. Hence, the circumference would be in terms of units of length like centimeters, meters, kilometers, feet, etc.

Circumference, C = 2πr where r is the radius

Circumference, C = πd where d is the diameter.

**Example 1: **

A circle has a radius of 14 cm. Can you find its circumference? Use \(\frac{22}{7}\) for π .

**Solution:**

C = 2πr Write the suitable formula for circumference

= \(2\times\frac{22}{7}\times 14\) Substitute \(\frac{22}{7}\) for π and 14 for r

= 88 centimeters

Hence, the circumference is 88 centimeters.

**Example 2:**

The diameter of a circular park is 70 meters. Find the circumference of the park. Use \(\frac{22}{7}\) for π .

**Solution:**

C = πd Write the suitable formula for circumference

= \(\frac{22}{7}\times 70\) Substitute \(\frac{22}{7}\) for π and 70 for d

= 220 meters

Hence, the circumference is 220 meters.

**Example 3:**

The circumference of a circular table is 110 centimeters. Find the radius of the circular table. Use \(\frac{22}{7}\) for 𝛑.

**Solution:**

C = 2𝛑r Write the suitable formula for circumference

110 = 2 × \(\frac{22}{7}\) × r Substitute \(\frac{22}{7}\) for 𝛑 and 110 for C

r = \(\frac{7×110}{44}\) Cross multiply by 7 and divide both side by 44

= 17.5 centimeters

Hence, the radius of the circular table is 17.5 centimeters.

**Example 4: **

The circumference of a circle is 220 meters. Find the diameter of the circle. Use \(\frac{22}{7}\) for 𝛑.

**Solution:**

C = 𝛑d Write the suitable formula for circumference

220 = \(\frac{22}{7}\) × d Substitute \(\frac{22}{7}\) for 𝛑 and 220 for C

d = \(\frac{7×220}{22}\) Cross multiply by 7 and divide both side by 22

= 70 meters

Hence, the diameter of the circle is 70 meters.

Frequently Asked Questions on Circumference of a Circle Calculator

Perimeter is defined as the sum of the lengths of the sides of an object. The perimeter of different flat shapes are measured in any unit that is used to measure length; including metres, centimetres, miles, feet, inches, etc.

Pi is a mathematical constant that can be used to calculate the area and circumference of a circle or other circular figures. We can get the value of pi when we divide the circumference of a circle by its diameter. Pi has the symbol \(\pi\), and its numerical value is about \(\frac{22}{7}\) = 3.142857…, it is an irrational number that is non-terminating and non-recurring. Furthermore, these numerical values are used based on the equation’s context.

The diameter of a circle is actually the longest chord of the circle that passes through the center of that circle. The circumference of a circle is equal to the length of the circle’s outer boundary. The diameter and circumference are both lengths that are measured in linear units. The circumference of a circle is equal to its diameter multiplied by the constant (pi).

The radius of a circle is half of the diameter or in other words, the diameter is two times the radius of the circle, \(r=\frac{d}{2}\) or d = 2r.

We know that infinite lines can be drawn through a single point. The diameter is a line segment that is drawn through the center of the circle. Hence, we can say that infinite diameters can be drawn for a circle. So, it would be impossible to count all of them!